Ruminants have four stomachs. Ruminants eat quickly and store masses of vegetation in the first chamber of the stomach, the rumen, where the vegetation softens.
The softening of the vegetation is extremely important in range fed cattle. The softening is due to saliva and the content of the saliva, as well as materials which are ingested with the vegetation.
The softened vegetation, called cud, is regurgitated. The cud is chewed with side-to-side grinding movement of the molars.
The chewed cud is swallowed and proceeds to the other chambers of the stomach, the reticulum, the omasum and the abomasum. The chewed material is further digested in those chambers by microorganisms that live in the stomach. It is said that, instead of feeding cattle one feeds the microorganisms, which then insure that the cattle are well fed.
Cattle feed supplements are intended to improve the conditions of microorganisms in the stomach chambers, and to maintain desired levels of minerals and nutrients in the circulatory system to feed cells to provide growth and reproductive support for breeding cattle. Minerals are also necessary to maintain desired contents of saliva to insure desired chemical content of an animal's stomach chambers, and particularly the rumen, to soften vegetation eaten by range animals by providing good conditions for digestive microorganisms in the rumen and in other stomach chambers.
Through years of experience with range feeding a lot of beef cattle and breeding herds, dietary requirements have become known. The National Research Council (NRC) has established mineral ingestion recommendations for cattle.
Minerals have been provided in block form in which minerals are mixed with salt, water and molasses, and are molded under high pressure. Blocks are placed in the field for use by cattle. Granular feeding of minerals has become popular. Granulated minerals are dumped into feeder bins or troughs. The animals are allowed to feed from the troughs by free choice. Sometimes a predetermined amount per head is calculated, and that amount times the number of head in a herd and the number of days between replenishment is placed in the feeders periodically, often two or three times a week.
Cafeteria-style selection has been provided in which individual minerals are placed in separate feeders, with the concept that cattle will choose the mineral supplements which are required. Cafeteria-style feeding requires increased labor.
Manufacturers of mineral supplements have tended to feed materials of similar mixtures, high in calcium. Purina Mills, for example, provides a mineral supplement having about 13% calcium.
Moorman Manufacturing Company of Comanche, Tex. provides mineral supplement of about 13% calcium and about 14.5% calcium.
Friona Industries of Friona, Tex. provides a mineral supplement of about 14% calcium.
S&S Animal Nutrition, Inc. of Morgan Mill, Tex. provides a mineral supplement having about 9.5% calcium.
Vit-A-Way, Inc. of Forth Worth, Tex., provides a mineral supplement having about 22% calcium.
Blue Bonnet Milling of Ardmore, Okla. has a mineral supplement with 11% calcium.
Those percentages are taken as an approximate mean between the stated contents of not less than and not more than. For example, Purina indicates not less than 12% and not more than 14% calcium.
A search for better and improved supplements continues.